The Study of Highway for Lifelong Multi-Agent Path Finding

In modern fulfillment warehouses, agents traverse the map to complete endless tasks that arrive on the fly, which is formulated as a lifelong Multi-Agent Path Finding (lifelong MAPF) problem. The goal of tackling this challenging problem is to find the path for each agent in a finite runtime while maximizing the throughput. However, existing methods encounter exponential growth of runtime and undesirable phenomena of deadlocks and rerouting as the map size or agent density grows. To address these challenges in lifelong MAPF, we explore the idea of highways mainly studied for one-shot MAPF (i.e., finding paths at once beforehand), which reduces the complexity of the problem by encouraging agents to move in the same direction. We utilize two methods to incorporate the highway idea into the lifelong MAPF framework and discuss the properties that minimize the existing problems of deadlocks and rerouting. The experimental results demonstrate that the runtime is considerably reduced and the decay of throughput is gradually insignificant as the map size enlarges under the settings of the highway. Furthermore, when the density of agents increases, the phenomena of deadlocks and rerouting are significantly reduced by leveraging the highway

Entanglement criterion via general symmetric informationally complete measurements

We study the quantum separability problem by using general symmetric informationally complete measurements and present a separability criterion for arbitrary dimensional bipartite systems. We show by detailed examples that our criterion is more powerful than the existing ones in entanglement detection.Comment: 8 pages, 5 figure

Energy-efficient Routing Model Based on Vector Field Theory for Large-scale Wireless Sensor Networks

Routing design is a key issue for large-scale wireless sensor networks (WSNs). Energy consumption associated with allocated resources should be considered. This paper proposes the integration of an energy-efficient model, which is based on vector field theory, in large-scale WSNs. Source nodes in WSNs have the characteristics of source points in a vector field, whereas sink nodes could be characterized as gathering points. Our scheme demonstrates that we can solve a set of partial differential equations in electrostatic theory to determine the routes that result in energy efficiency. Thus, the routing problem in WSN for energy efficiency becomes a typical PDE solution. Our simulation results show significant improvement in energy consumption. Compared with the traditional shortest path approach, the proposed model shows considerable improvement in the lifetime of the network